First Alert/BRK 9120B / SC-9120B Hardwired vs First Alert SMCO100 / SMCO200V Combo

Side-by-side specs from each maker.

Only the differences are shown.

First Alert 9120BFirst Alert SMCO100 / SMCO200V Combo
TypeSmoke or CO alarmSmoke or CO alarm
Alarmsmokecombo
SensorionizationPhotoelectric (smoke) and electrochemica
PowerHardwired 120-volt with 9V battery backupAA (2 alkaline, replaceable)
InterconnectwiredNot listed
Replace afterNot listed10 years

First Alert/BRK 9120B / SC-9120B Hardwired

An older hardwired ionization smoke alarm with 9V battery backup.

  • Interconnects with up to 12 other First Alert or BRK hardwired smoke detectors and 6 other compatible devices
  • 9V battery included
  • Ionization sensing only

First Alert SMCO100 / SMCO200V Combo

A battery-powered smoke and CO combo alarm that runs on two replaceable AA batteries. The maker says the unit itself should be replaced at least every 10 years.

  • Replaceable AA batteries
  • The maker lists a replacement interval of at least every 10 years